Monday, June 21, 1999 Published at 12:33 GMT 13:33 UKWorld: AmericasLie detector tests for US nuclear scientistsFears of Chinese espoinage are driving security measuresThe US Government has reportedly introduced lie detector tests for some 5,000 people working on the most secret parts of its nuclear weapons programme.

Energy Secretary Bill Richardson ordered the testing following recent allegations that Chinese spies had stolen nuclear secrets from its national laboratories, according to the Washington Post.

But Mr Richardson said he anticipated opposition to the tests from some laboratories and civil liberties groups. ''I fully expect lawsuits," he added.

Staff groups have already suggested they will challenge the tests which are being given to nuclear scientists and other workers in sensitive positions.

A Congressional report last month said China stole secrets
on seven US nuclear warheads and the neutron bomb during 20 years of espionage.

Testing may backfire

However, there is growing debate in America on the scientific reliability of polygraph testing.

Bill Richardson: Trying to repair security lapses

Studies have found that the number of mistakes rise with the IQ of the person being tested, meaning brilliant scientists may be more likely to incriminate themselves with false readings.

Mr Richardson said he was concerned that the introduction of tests could hurt his department's ability to recruit first-rate scientists.

But he said he decided it was important to join the CIA and National Security Agency, the only federal agencies with widespread polygraph programmes, to send a message that protecting nuclear secrets was a top priority.

Speaking on US television, he said a number of government employees found responsible for security problems at nuclear laboratories would be fired "in the next weeks".

'Accident waiting to happen'

Former Senator Warren Rudman, who investigated the Department of Energy's counter-intelligence performance, said a directive issued early last year to introduce polygraph tests for scientists and better security checks for foreign visitors still had not been fully implemented.

"These weapons are not safe. These secrets are not safe. We have a terribly long way to go. It's been an accident waiting to happen for 20 years," he added.